Re: Instance & Database

You pose an interesting question. An Oracle instance is comprised of the daemon processes which may or may not be connected to an actual database.  This is the case when a new database is being created. The instance is "attached" to a physical database when the database is both mounted and opened. Therefore a single instance may be connected to only one physical database. However, when running in parallel, mutiple instance can be attached to a single database.

Please be careful when defining a database. Some persons have tried to extend PC orientations to an Oracle environment. A single Oracle database may service a virtually unlimited number of applications. I am reminded of one instance when I suggested that a moderately sized business might need only one Oracle database. The person with whom I was speaking increduously asked, "You can't use a single database to run the whole company, can you?" You can indeed! There are companies using Oracle to manage multiple terabyte databases. Received on Sun Nov 12 1995 - 00:00:00 CET